Abstract:Protoplasts isolated from monokaryotic mycelia of Lentinus edodes were spread on CM containing 0.6 mol /1 sucrose and irradiated for 30 seconds. After colonies formed, they were transplanted on MM anfl those showing little growth were detected further. 7 auxotrophic mutants were obtained at last, among which 3 mutants remained stable after protoplast isolation, regeneration and mycelial subculture on CM slant for 3 times. They can be used in protoplast fusion in later studies, despite their protoplast yields were low and have to be improved.